U.S. patent application number 15/224924 was filed with the patent office on 2017-03-09 for image forming apparatus, image forming method, and sheet-feeding apparatus.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Shinnosuke Iwadate, Teruhito Kai, Hiroto Nishihara, Hiromi Shimura, Keita Takahashi, Kentaro Tamura.
Application Number | 20170066610 15/224924 |
Document ID | / |
Family ID | 58189348 |
Filed Date | 2017-03-09 |
United States Patent
Application |
20170066610 |
Kind Code |
A1 |
Kai; Teruhito ; et
al. |
March 9, 2017 |
IMAGE FORMING APPARATUS, IMAGE FORMING METHOD, AND SHEET-FEEDING
APPARATUS
Abstract
Provided is an image forming apparatus including a manual feed
tray for placing a sheet subjected to image formation, a sheet
sensor configured to detect whether or not the sheet is placed on
this manual feed tray, a pickup roller configured to feed the sheet
placed on the manual feed tray, and a controller. When a size of a
sheet to be fed is designated by a user, and it is determined that
the sheet is placed, the controller causes at least one of the
pickup roller and the manual feed tray to start movement to a
position of enabling the pickup roller to feed the placed
sheet.
Inventors: |
Kai; Teruhito; (Kashiwa-shi,
JP) ; Iwadate; Shinnosuke; (Toride-shi, JP) ;
Nishihara; Hiroto; (Tsukuba-shi, JP) ; Shimura;
Hiromi; (Toride-shi, JP) ; Takahashi; Keita;
(Abiko-shi, JP) ; Tamura; Kentaro; (Komae-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
58189348 |
Appl. No.: |
15/224924 |
Filed: |
August 1, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2801/03 20130101;
B65H 2511/11 20130101; B65H 5/062 20130101; B65H 3/0684 20130101;
B65H 7/02 20130101; G03G 15/6552 20130101; G03G 15/6514 20130101;
G03G 15/5016 20130101 |
International
Class: |
B65H 7/02 20060101
B65H007/02; B65H 5/06 20060101 B65H005/06; B65H 3/06 20060101
B65H003/06; G03G 15/00 20060101 G03G015/00; B65H 1/04 20060101
B65H001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 4, 2015 |
JP |
2015-174950 |
Claims
1. An image forming apparatus, comprising: a manual feed tray on
which a sheet subjected to image formation is placed; a determining
unit configured to determine whether the sheet is placed on the
manual feed tray or not; a sheet-feeding unit configured to feed
the sheet placed on the manual feed tray; and a controller,
wherein, in a case where a size of a sheet to be placed on the
manual feed tray is designated by a user in advance and the
determining unit determines that the sheet is placed, the
controller causes at least one of the sheet-feeding unit and the
manual feed tray to start movement so that the sheet-feeding unit
and the manual feed tray approach to each other.
2. An image forming apparatus according to claim 1, wherein the
controller causes the at least one of the sheet-feeding unit and
the manual feed tray to be moved to a position of enabling the
sheet-feeding unit to feed the placed sheet.
3. An image forming apparatus according to claim 1, further
comprising a size detection unit configured to detect a size of a
sheet placed on the manual feed tray, wherein the controller causes
the movement to be started when the detected size and the
designated size are matched.
4. An image forming apparatus according to claim 3, wherein the
controller causes the movement of the sheet-feeding unit to be
prevented from being started when the detected size and the
designated size do not match.
5. An image forming apparatus according to claim 3, wherein the
size detection unit comprises: a first sensor configured to detect
a length of a sheet placed on the manual feed tray in a conveying
direction; and a second sensor configured to detect a length of a
sheet placed on the manual feed tray in a direction intersecting
with the conveying direction, wherein the controller determines a
size of a sheet placed on the manual feed tray in accordance with
detection results of the first sensor and the second sensor.
6. An image forming apparatus according to claim 1, wherein, when
sheet feeding is not performed even after elapse of a predetermined
time period from the movement, the controller causes the at least
one of the sheet-feeding unit and the manual feed tray to be moved
in a direction of separating the sheet-feeding unit and the manual
feed tray.
7. An image forming apparatus according to claim 1, wherein, when
the determining unit determines that the sheet is not placed after
the movement, the controller causes the at least one of the
sheet-feeding unit and the manual feed tray to be moved in a
direction of separating the sheet-feeding unit and the manual feed
tray.
8. An image forming apparatus, further comprising an interface unit
configured to receive input from a user, wherein a size of the
sheet to be fed is designated through the interface unit.
9. An image forming apparatus according to claim 8, wherein the
interface unit includes a screen, and wherein, when a size of a
sheet to be fed onto the manual feeding tray is not designated by a
user in advance, the controller causes the screen of the interface
unit to display a selection screen for a size of a sheet to be
fed.
10. An image forming apparatus according to claim 1, wherein the
sheet-feeding unit is movable, and wherein the controller causes
the sheet-feeding unit to be moved toward the manual feed tray to
enable the sheet-feeding unit to feed the placed sheet.
11. An image forming apparatus according to claim 1, wherein the
manual feed tray is movable, and wherein the controller causes the
manual feed tray to be moved toward the sheet-feeding unit to
enable the sheet-feeding unit to feed the placed sheet.
12. An image forming method to be performed by an image forming
apparatus, the image forming apparatus comprising: a manual feed
tray on which a sheet subjected to image formation is placed; and a
sheet-feeding unit configured to feed the sheet placed on the
manual feed tray, the image forming method comprising: determining
whether or not the sheet is placed on the manual feed tray; and
when a size of a sheet to be fed onto the manual feed tray is
designated by a user in advance, and in a case where the sheet is
placed on the manual feed tray, starting movement of at least one
of the sheet-feeding unit and the manual feed tray so that the
sheet-feeding unit and the manual feed tray approach to each
other.
13. A sheet-feeding apparatus, which is to be connected to an image
forming apparatus and configured to perform sheet feeding,
comprising: a manual feed tray on which a sheet to be fed to the
image forming apparatus is placed; a determining unit configured to
determine whether the sheet is placed on the manual feed tray or
not; a sheet-feeding unit configured to feed the sheet placed on
the manual feed tray to the image forming apparatus; and a
controller, wherein, in a case where a size of a sheet to be fed
onto the manual feed tray is designated by a user in advance and
the determining unit determines that the sheet is placed, the
controller causes at least one of the sheet-feeding unit and the
manual feed tray to start movement so that the sheet-feeding unit
and the manual feed tray approach to each other.
Description
BACKGROUND OF THE INVENTION
[0001] Field of the Invention
[0002] The present disclosure relates to an image forming
apparatus, an image forming method, and a sheet-feeding apparatus.
More particularly, the present disclosure relates to a
sheet-feeding control for a copying machine, a printer, and the
like, which are configured to perform image formation on a sheet,
such as a sheet.
[0003] Description of the Related Art
[0004] An electrophotographic image forming apparatus includes a
sheet-feeding cassette and a sheet-feeding tray, e.g., a manual
feed tray, and is configured to feed a sheet placed on the
sheet-feeding cassette or the sheet-feeding tray to an image
forming section for performing image formation. In particular, when
image formation is performed on a thick sheet, a coated sheet, or
another sheet having a large basis weight which cannot be handled
by the sheet-feeding cassette, the manual feed tray is widely
used.
[0005] In Japanese Patent Application Laid-open No. Hei 7-97079,
there is disclosed a drive transmission mechanism including a
pickup roller configured to feed a sheet placed on a manual feed
tray and a sheet-feeding roller located downstream in a conveying
direction. The pickup roller and the sheet-feeding roller are
driven by the same drive power source. A support arm for the pickup
roller is swung upward and downward each time the pickup roller
performs sheet feeding, thereby allowing an uppermost sheet on the
sheet-feeding tray to be fed to an image forming section one after
another.
[0006] Further, hitherto, there has been a demand for an image
forming apparatus to shorten a first copy time, which is a time
period from pressing a copy key to outputting a first copy. As a
matter of course, it is desired that the first copy time be
shortened also in the case of sheet feeding from the manual feed
tray described above.
[0007] There has been widely known a function called "fixed size
mode" of setting in advance a size of a sheet to be used with the
manual feed tray for the purpose of improving usability for a user
who frequently uses the manual feed tray. Enabling this function
can eliminate an annoying operation of performing size setting
through an operation unit each time the manual feed tray is
used.
[0008] However, in the related art, the pickup roller is raised
each time one sheet is fed from the manual feed tray regardless of
whether or not the fixed size mode is enabled. As a result, the
pickup roller waits at an upper limit position, which is an initial
position, when a sheet-feeding operation is not performed. When
printing is started, sheet feeding is delayed by a time period of
lowering the pickup roller from the upper limit position to a
surface of a sheet on the manual feed tray for sheet feeding and a
waiting time until vibration of the pickup roller on the sheet is
ceased. This delay time may cause the first copy time to be
lengthened.
SUMMARY OF THE INVENTION
[0009] An image forming apparatus according to the present
disclosure comprises: a manual feed tray for placing a sheet
subjected to image formation; a determining unit configured to
determine whether the sheet is placed on the manual feed tray or
not; a sheet-feeding unit configured to feed the sheet placed on
the manual feed tray; and a controller, wherein, in a case where a
size of a sheet to be fed onto the manual feed tray is designated
by a user in advance and the determining unit determines that the
sheet is placed, the controller causes at least one of the
sheet-feeding unit and the manual feed tray to start movement so
that the sheet-feeding unit and the manual feed tray approach to
each other.
[0010] Further features of the present invention will become
apparent from the following description of exemplary embodiments
(with reference to the attached drawings).
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a sectional view for illustrating an image forming
apparatus main body.
[0012] FIG. 2 is a functional block diagram of the image forming
apparatus.
[0013] FIG. 3 is a sectional view for illustrating a manual feed
tray.
[0014] FIG. 4 is a plan view for illustrating the manual feed
tray.
[0015] FIG. 5 is a graph for showing a relationship between a main
scanning length and a sheet width sensor.
[0016] FIG. 6 is a data table for showing a relationship between
detection results of sensors and sheet sizes.
[0017] FIG. 7A, FIG. 7B, FIG. 7C, and FIG. 7D are explanatory views
for illustrating a user interface.
[0018] FIG. 8A and FIG. 8B are explanatory views for illustrating
raising and lowering operations of the pickup roller.
[0019] FIG. 8C is a timing chart for illustrating the raising and
lowering operations of the pickup roller.
[0020] FIG. 9 is a flowchart for illustrating a control which is
executed when a sheet is set on the manual feed tray.
[0021] FIG. 10 is a flowchart for illustrating the pickup roller
lowering sub-flow.
[0022] FIG. 11 is a flowchart for illustrating a control which is
executed when power is turned on.
[0023] FIG. 12 is a flowchart for illustrating a control which is
executed when a print job is started.
DESCRIPTION OF THE EMBODIMENTS
<Schematic Configuration of Image Forming System>
[0024] FIG. 1 is a sectional view for illustrating an image forming
apparatus 10 according to a first embodiment of the present
invention. Further, FIG. 2 is a functional block diagram of the
image forming apparatus 10. Now, the first embodiment is described
with reference to FIG. 1 and FIG. 2.
<Schematic Configuration of Image Forming Apparatus>
[0025] As illustrated in FIG. 1, the image forming apparatus 10
according to this embodiment can forma color image with toners of
four colors, that is, a plurality of colors including yellow (y),
magenta (m), cyan (c), and black (k). Further, image formation can
also be performed with one color (single color) selected from among
the toners of four colors. In this description, an exemplary case
is described in which single color image formation is monochromatic
printing (black).
[0026] Further, the image forming apparatus 10 can be connected to
a computer 283 or other device (for example, a facsimile machine)
through an external I/F 282 illustrated in FIG. 2.
[0027] The image forming apparatus 10 includes laser scanner units
103, primary transfer rollers 105 (y, m, c, and k) serving as
transfer members, an intermediate transfer belt 130 which is one
example of a transfer belt, a fixing unit 170, and a manual feed
tray 111 configured to receive a sheet (e.g., a sheet). Now, an
example of using a sheet as a sheet is described.
[0028] The image forming apparatus 10 further includes a pickup
roller 113 configured to operate as a movable sheet-feeding unit,
sheet-feeding rollers 114, a sheet sensor 115, a registration
roller 116, a secondary transfer unit 118, image forming units 120,
and a sheet delivery roller 139. Yet further, the image forming
apparatus 10 includes a sheet delivery tray 132, an operation unit
(hereinafter referred to as UI (user interface)) 330, an original
holder 152, an original conveying roller 112, an original
presence/absence sensor 151, an image sensor 233, and an original
glass 55. The sheet sensor 115 is configured to detect whether or
not a sheet is present on the manual feed tray 111.
[0029] The image forming units 120 include photosensitive drums 101
(y, m, c, and k), charging rollers 102 (y, m, c, and k), developing
units 104 (y, m, c, and k), and photosensitive drum cleaners 107
(y, m, c, and k), respectively.
[0030] The controller 300 illustrated in FIG. 2 includes a CPU
(Central Processing Unit) 301, a ROM (Read Only Memory) 302, a RAM
(Random Access Memory) 303, and a timer 291. The CPU 301 of the
controller 300 is configured to execute a control of the image
forming apparatus 10. The ROM 302 storing a control program written
therein and the RAM 303 configured to store variables for use in
the control and image data read by the image sensor 233 are
connected to the CPU 301 through an address bus and a data bus. The
timer 291 capable of counting time is connected to the CPU 301. The
CPU 301 is configured to set a time count value for the timer 291
and obtain a timer measurement value from the timer 291.
[0031] The CPU 301 is configured to drive the original conveying
roller 112 through an original feeder controller 480 and detect
presence of an original through the original presence/absence
sensor 151. Further, the CPU 301 is configured to detect opening
and closing operations of an original pressing plate through an
image reader controller 280. Further, the CPU 301 is configured to
obtain an image of an original on the original glass 55 or an image
of an original fed by the original feeder controller 480 through
the image sensor 233. After that, the CPU 301 transfers an analog
image signal obtained from the image sensor 233 to an image signal
controller 281.
[0032] During a copying operation, the image signal controller 281
executes processing which is necessary for the copying operation
after converting the analog image signal from the image sensor 233
into a digital image signal, converts the processed digital image
signal into a video signal, and outputs the video signal to a
printer controller 285. Further, during the printing operation, the
image signal controller 281 executes various necessary processing
to a digital image signal input from the computer 283 through the
external I/F 282, converts the digital image signal into a video
signal, and outputs the video signal to the printer controller
285.
[0033] The printer controller 285 instructs image formation to the
image formation control unit 271 based on an instruction from the
CPU 301. The image formation control unit 271 drives the image
forming units 120 in accordance with the input video signal.
Further, in accordance with an instruction from the CPU 301, the
image formation control unit 271 controls a sheet conveying unit
270 to feed and convey a sheet, and controls raising and lowering
operations of the pickup roller 113. Further, the CPU 301
determines through the printer controller 285 whether a sheet is
placed on the manual feed tray 111 of FIG. 1 or not. In this
embodiment, the CPU 301 determines that a sheet is placed when the
sheet is detected by the sheet sensor 115 illustrated in FIG.
1.
[0034] The UI 330 is an operation unit of the image forming
apparatus 10. Through the UI 330, a user gives instructions, such
as selection of a color mode in image formation, indication of a
state of the image forming apparatus 10, and start of copying. When
the CPU 301 detects that a sheet is set on the manual feed tray
111, the CPU 301 causes a sheet size selection screen to be
displayed on the UI 330. The mode setting selected through this
operation is stored in the RAM 303.
<Basic Image Forming Operation of Image Forming
Apparatus>
[0035] Next, a basic image forming operation is described with
reference to FIG. 1 and FIG. 2. The CPU 301 detects through the
sheet sensor 115 that a sheet is set on the manual feed tray 111,
and causes the sheet size selection screen to be displayed on the
UI 330. When the sheet size is selected and settled by a user, the
CPU 301 causes the pickup roller 113 to perform raising and
lowering operations. As a result, a position of the pickup roller
113 is moved to a pickup roller abutment position where a nip
portion is formed with a sheet placed on the manual feed tray
111.
[0036] The CPU 301 detects print setting instructions of a color
mode, the number of prints, and other settings through the UI 330.
Then, the CPU 301 detects opening and closing of the original
pressing plate and placement of an original through the original
feeder controller 480 and the image reader controller 280. The CPU
301 performs print preparation operation after detection of those
print setting instructions, opening and closing of the original
pressing plate, and placement of an original.
[0037] During the print preparation operation, the CPU 301 starts a
temperature adjustment control for the fixing unit 170. When a size
of a sheet on the manual feed tray 111 is settled, the CPU 301
detects whether or not the pickup roller 113 is located at a
position held in abutment against a sheet (hereinafter simply
referred to as "abutment position"). When the pickup roller 113 is
not located at the abutment position, the position of the pickup
roller 113 is moved to the abutment position. The raising and
lowering operations of the pickup roller 113 and the print
preparation operation are described later in detail.
[0038] Next, when the start of the printing operation is notified
through the UI 330, the CPU 301 starts reading of an original
through the original feeder controller 480. Further, the CPU 301
drives the original conveying roller 112 to convey an original from
the original holder 152 to a position above a platen glass and
radiates light of a lamp (not shown) to the original through the
platen glass.
[0039] Reflected light from the original is guided to the image
sensor 233, and image data of the original read by the image sensor
233 is output to the image signal controller 281. Reading of the
original is continued until reading of the original on the original
glass 55 is completed or until reading of the last original
detected by the original presence/absence sensor 151 is
completed.
[0040] The CPU 301 controls the image forming units 120 (y, m, c,
and k) through the image formation control unit 271 to start image
forming operation of image data stored in the RAM 303.
[0041] The image forming units 120 (y, m, c, and k) include the
photosensitive drums 101 (y, m, c, and k), the developing units 104
(y, m, c, and k), the charging rollers 102 (y, m, c, and k), and
the photosensitive drum cleaners 107 (y, m, c, and k),
respectively. In the image forming units 120 (y, m, c, and k),
surfaces of the photosensitive drums 101 are charged, and latent
images are formed on the photosensitive drums 101 (y, m, c, and k)
by laser beams radiated from the laser scanner units 103 (y, m, c,
and k), respectively.
[0042] The formed latent images are developed on the photosensitive
drums 101 by the toners in the developing units. After that, toner
images developed on the photosensitive drums 101 are applied with a
primary transfer voltage at a monochromatic primary transfer roller
105k and color primary transfer rollers 105 (y, m, and c) and
transferred onto the intermediate transfer belt 130. The toner
images transferred onto the intermediate transfer belt 130 reach
the secondary transfer unit 118 through rotation of the
intermediate transfer belt 130.
[0043] Through the sheet conveying unit 270, the CPU 301 drives, a
motor (not shown) which serves as a drive source for the pickup
roller 113, the sheet-feeding rollers 114, the registration roller
116, and the sheet delivery roller 139. This driving is performed
so as to coincide with the timing at which the toner images arrive
at the secondary transfer unit 118. As a result, the pickup roller
113 is driven to rotate, and hence sheets are fed and conveyed one
after another from the manual feed tray 111.
[0044] In such a manner as described above, the secondary transfer
voltage is applied to the sheet and the toner images having reached
the secondary transfer unit 118, to thereby transfer the toner
images to the sheet.
[0045] The sheet after the secondary transfer is conveyed to the
fixing unit 170. In the fixing unit 170, the toner images on the
sheet are heated and fixed on the sheet. After that, the CPU 301
performs delivery of the sheet to the sheet delivery tray 132
through the sheet delivery roller 139 controlled by the sheet
conveying unit 270. After the printing operation is completed, the
CPU 301 causes the pickup roller 113 to be moved upward from the
position held in abutment against the manual feed tray 111 to a
pickup roller separation position.
[0046] The above-mentioned basic image forming operation is one
example, and the present invention is not limited to the
above-mentioned configuration.
<Configuration to Detect Sheet>
[0047] With reference to FIG. 3, a configuration to detect a sheet
placed on the manual feed tray 111 according to the first
embodiment is described.
[0048] FIG. 3 is a sectional view for illustrating the manual feed
tray 111. When a sheet P is set on the manual feed tray 111, a
sheet flag 411 configured to detect presence of the sheet P is
pushed and moved by the sheet P and shades the sheet sensor 115.
When the sheet sensor 115 is shaded, the sheet sensor 115 detects
that the sheet P is present on the manual feed tray 111. As a
result, the CPU 301 can determine that the sheet P is placed on the
manual feed tray 111. Further, the manual feed tray 111 includes a
first detection flag 412 configured to detect a sheet length in a
conveying direction of the sheet P set on the manual feed tray 111.
When the sheet P is set, the sheet length can be detected based on
whether or not the first sensor 218 is shaded. Similarly, a second
detection flag 413 and a second sensor 219 are provided in the
manual feed tray 111 to detect a sheet length.
[0049] In a case where a function to register a fixed size of a
sheet to be placed on the manual feed tray (hereinafter referred to
as fixed size mode), which is described later, is not enabled, when
the sheet P is set on the manual feed tray 111, the CPU 301 causes
the sheet size selection screen to be displayed on the UI 330.
Meanwhile, in a case where the fixed size mode is enabled, even
when the sheet P is set on the manual feed tray 111, the CPU 301
does not cause the sheet size selection screen to be displayed on
the UI 330. Details of display on the UI 330 are described
later.
[0050] Further, rotation of the sheet-feeding conveyance motor 164
under a state in which the pickup roller 113 is held in abutment
against the sheet P causes the pickup roller 113 and the
sheet-feeding rollers 114 to be rotated, to thereby feed and convey
the sheet P in a direction indicated by the arrow.
<Detection of Size of Sheet on Manual Feed Tray>
[0051] Next, with reference to FIG. 4 and FIG. 5, a method of
determining a size of a sheet set on the manual feed tray 111
according to the first embodiment is described.
[0052] FIG. 4 is a plan view for illustrating the manual feed tray
111. A bundle of sheets set on the manual feed tray 111 is clamped
by the manual feed side regulation guides 212 and 213 so as to be
prevented from being conveyed obliquely during conveyance by the
pickup roller 113. Further, when sheets having different main
scanning lengths are set, the manual feed side regulation guides
212 and 213 slide in the directions of the arrows 215 and 216. With
this, oblique movement of the sheets is prevented. Further, the
manual feed side regulation guides 212 and 213 are coupled to a
sheet width sensor 217 through a link (not shown), and a value
corresponding to a position of the manual feed side regulation
guide 212 is input to the CPU 301. The sheet width sensor 217 is
configured to detect a length of a sheet in a width direction
orthogonal to the conveying direction of the sheet (hereinafter
referred to as sheet width).
[0053] The CPU 301 performs detection of a sheet width in the width
direction based on the input value. Further, the CPU 301 detects
whether or not the first sensor 218 is shaded by the first
detection flag 412 to thereby detect a sheet length of a sheet set
on the manual feed tray 111. Similarly, the CPU 301 detects whether
or not the second sensor 219 is shaded by the second detection flag
413 to thereby detect a sheet length of a sheet set on the manual
feed tray 111.
[0054] In FIG. 5, there is shown a relationship between an output
value of the sheet width sensor 217, which may vary in accordance
with the movement of the manual feed side regulation guides 212 and
213, and a sheet width which is actually detected. Specifically,
the sheet width sensor 217 is a sensor configured to output a
10-bit value, and outputs output values of from 0 to 0x400
substantially proportional to the sheet widths.
[0055] In FIG. 5, the output value 0x320 of the sheet width sensor
217 indicates 210 mm which is an A4R width. Similarly, the output
value 0x384 indicates 257 mm which is a B4R width, and the output
value 0x3D4 indicates 297 mm which is an A4 width.
[0056] The CPU 301 specifies the sheet size in accordance with an
output value of the sheet width sensor 217 and outputs from the
first sensor 218 and the second sensor 219. A data table which is
referred by the CPU 301 to specify the sheet size is shown in FIG.
6.
[0057] As shown in FIG. 6, when it is provided that a manually fed
sheet presence/absence sensor 214 being in an ON state, the first
sensor 218 being in an OFF state, the second sensor 219 being in an
OFF state, and an output value of the sheet width sensor 217 being
0x320.+-.0x010, the size of the sheet is specified as an A5 size.
An output value of the sheet width sensor 217 corresponding to the
A5 size is 0x320. In this embodiment, when it is provided that the
detection error of the sheet width sensor being 0x010, and the
output value of the sheet width sensor 217 being within the range
of 0x320.+-.0x010, the size of the sheet is the A5 size.
[0058] Similarly, when it is provided that the manually fed sheet
presence/absence sensor 214 being in an ON state, the first sensor
218 being in an ON state, the second sensor 219 being in an OFF
state, and the output value of the sheet width sensor 217 being
0x320.+-.0x010, the size of the sheet is specified as an A4R size.
In such a manner, even when the output value of the sheet width
sensor 217 is the same, the sheet size can be identified based on
the difference in output of the first sensor 218 or the second
sensor 219.
[0059] When the size of the sheet is the B5 size, the outputs of
the first sensor 218 and the second sensor 219 are the same as
those of the case where the size of the sheet is the A5 size.
However, the output value of the sheet width sensor 217 is
0x384.+-.0x010, and hence the sheet size can be determined based on
the difference in the output value of the sheet width sensor
217.
<Description of UI>
[0060] FIG. 7A to FIG. 7D are explanatory views of the UI screen.
FIG. 7A is an explanatory view for illustrating a screen of the UI
330 according to the first embodiment. On the UI 330, there are
arranged a start key 306 for starting the copying operation, a stop
key 307 for stopping the copying operation, numerical keys 313 for
performing setting of the number of prints, and other keys.
Further, there is also arranged a display portion 311 having a
touch panel formed on a surface portion thereof, and soft keys can
be created on the screen. On a sheet size display portion 312, copy
setting is displayed. In this example, magnification is set to be
100% (same size), and sheet selection is set to be "AUTOMATIC
SHEET". Further, the CPU 301 executes a printing preparation
operation control in response to operation to the numerical keys
313 for performing setting of the number of sheets.
[0061] In FIG. 7B, a sheet size selection screen is illustrated
which is displayed on the display portion 311 when the sheet P is
set on the manual feed tray 111 under a state in which the fixed
size mode is disabled. Under a state in which the fixed size mode
is enabled, the size of the sheet to be used is set in advance by a
user, and hence the sheet size selection screen is not displayed.
Details of the fixed size mode are described later.
[0062] On the display portion 311, there are arranged an A5 button
321, an A4 button 322, an A3 button 323, an A5R button 324, an A4R
button 325, a B5 button 326, a B4 button 327, and a B5R button 328.
When an OK button 329 is pressed under a state in which any one of
the buttons is selected, the sheet size is settled, and data
representing the settled sheet size is stored in the RAM 303. After
the sheet size is settled, when the CPU 301 determines that no
sheet is present on the manual feed tray 111 based on the sheet
sensor 115, the sheet size is unsettled, and the result is also
stored in the RAM 303. After that, when the sheet P is set on the
manual feed tray 111, the sheet size selection screen is displayed
again. The printing operation cannot be started until the sheet
size is settled.
[0063] FIG. 7C and FIG. 7D are setting screens for the fixed size
mode. When a fixed size mode setting button 335 arranged on the
display portion 311 of FIG. 7A is pressed, shifting to the fixed
size mode setting screen is performed.
[0064] When the size of the sheet to be used is set through the
fixed size mode in advance, a user does not need to perform sheet
size setting through the display portion 311 each time a user sets
the sheet P on the manual feed tray 111. In the setting screen for
the fixed size mode, there are arranged a mode enabling button 331,
a mode disabling button 332, a sheet size registration button 333,
and an OK button 334.
[0065] FIG. 7C is an illustration of a screen of the display
portion 311 when the fixed size mode is enabled. When the sheet
size registration button 333 is pressed under a state in which the
mode enabling button 331 is selected, the sheet size can be set
through the screen illustrated in FIG. 7B. When the OK button 329
is pressed under a state in which any one of the buttons 321 to 328
is selected, the screen illustrated in FIG. 7C is displayed. Next,
when the OK button 334 is pressed, the fixed size mode is enabled
with the selected sheet size. The CPU 301 stores information
indicating that the fixed size mode is enabled in the RAM 303.
[0066] Now, the selected sheet size is described as the fixed size
in the fixed size mode. For example, when the fixed size mode with
the fixed size of A4 size is set, and a job which is designated to
feed a sheet from the manual feed tray 111 is input, "A4" is
displayed on the sheet size display portion 312 illustrated in FIG.
7A.
[0067] FIG. 7D is an illustration of a screen displayed when the
fixed size mode is not enabled, that is, the fixed size mode is
disabled. When a user presses the OK button 334 under a state in
which the mode disabling button 332 is selected, information
indicating that the fixed size mode is disabled is stored in the
RAM 303. When a job which is designated to feed from the manual
feed tray 111 is input under a state in which the fixed size mode
is disabled, it is displayed on the sheet size display portion 312
that the sheet size can be set by a user ("AUTOMATIC").
<Raising and Lowering Operations of Pickup Roller>
[0068] FIG. 8A and FIG. 8B are explanatory views for illustrating
the raising and lowering operations of the pickup roller 113
according to the first embodiment. FIG. 8C is a timing chart for
illustrating the raising and lowering operations of the pickup
roller 113 according to the first embodiment.
[0069] FIG. 8A is a plan view for illustrating the pickup roller
113 of a manual sheet-feeding unit and a sheet-feeding arm 160
configured to support the pickup roller 113. The pickup roller 113
is supported by the sheet-feeding arm 160 through a pickup roller
shaft 161. A sheet-feeding arm shaft 162 is fixed to the
sheet-feeding arm 160, and is configured such that driving of a
raising and lowering motor 163 is transmitted thereto through a cam
(not shown).
[0070] The raising and lowering operations of the pickup roller 113
are described with reference to a schematic explanatory view of the
manual sheet-feeding unit illustrated in FIG. 8B. As illustrated in
FIG. 8B, when the raising and lowering motor 163 is driven, the
sheet-feeding arm shaft 162 is reciprocally rotated within a
certain angular range through the above-mentioned cam. The
sheet-feeding arm shaft 162 is fixed to the sheet-feeding arm 160,
and the sheet-feeding arm 160 is raised and lowered through
rotation about the sheet-feeding arm shaft 162 as a supporting
point. The pickup roller 113 is raised and lowered in the
directions of the arrow Dl in conjunction with raising and lowering
of the sheet-feeding arm 160. When the pickup roller 113 is located
at a pickup roller separation position which is a position most
distant from the manual feed tray 111, a pickup roller HP sensor
167 is shaded by the sheet-feeding arm 160. The pickup roller HP
sensor 167 is a sensor configured to detect that the pickup roller
113 is located at a home position. This home position is also a
position of the pickup roller 113 when a sheet is not placed on the
manual feed tray 111, and it is a position distant (raised) from
the manual feed tray 111.
[0071] FIG. 8C is a timing chart for illustrating a relationship
among driving of the raising and lowering motor 163, positions of
the pickup roller 113, and the pickup roller HP sensor 167, with a
horizontal axis representing time t.
[0072] The raising and lowering operations of the pickup roller 113
are described. As described above, when the size of a sheet is
settled, the pickup roller 113 starts lowering from the separation
position, which is a position distant from the manual feed tray
111, at a timing T1. At a timing T2 after elapse of a predetermined
time period Ta (500 [ms] in this embodiment), the pickup roller 113
is moved to an abutment position which is closest to the manual
feed tray 111. After that, the CPU 301 turns off driving of the
raising and lowering motor 163 to hold the pickup roller 113 at the
abutment position.
[0073] As described above, the pickup roller 113 is moved to the
abutment position before the printing operation start instruction
is received, and then the printing operation start instruction is
received when the pickup roller 113 is located at the abutment
position, thereby shortening a first copy output time (FCOT) by the
predetermined time period Ta. Next, at a timing T3 after feeding of
sheets of the number designated by a job is completed, the CPU 301
turns on driving of the raising and lowering motor 163, thereby
causing the pickup roller 113 to start raising from the abutment
position. At a timing T4 of detecting an ON edge of the pickup
roller HP sensor 167, it is determined that the pickup roller 113
has been moved to the separation position, and then driving of the
pickup roller raising and lowering motor 163 is turned off to hold
the pickup roller 113 at the separation position in the same
way.
[0074] In the first embodiment, when the CPU 301 detects that a
sheet is present on the manual feed tray 111 under a state in which
the fixed size mode is enabled, the CPU 301 determines whether or
not the size designated by a user matches with a size detection
result. When the designated size matches with the size detection
result, the CPU 301 causes the pickup roller 113 to be moved to the
abutment position. Accordingly, sheet feeding can be performed
immediately in response to a printing start instruction. As a
result, the FCOT is shortened by a time period necessary for the
pickup roller 113 to be brought into abutment against the sheet as
compared to the configuration in which the pickup roller 113 is
lowered after receiving an instruction to start printing.
[0075] When the fixed size mode is enabled, the sheet size is
settled in advance by a user through the UI 330. Therefore, under a
state in which the fixed size mode is enabled, the CPU 301 causes
the pickup roller 113 to be moved to the abutment position in
response to the detection that a sheet having a size matched with a
fixed size is present on the manual feed tray 111. The reason for
this is described in detail.
[0076] When the pickup roller 113 is held in abutment against the
sheet, the pickup roller 113 is pressed toward the tray side to
some extent to feed a sheet from the manual feed tray 111. Even in
such a case, a user can remove the sheet from the manual feed tray
111.
[0077] However, when the pickup roller 113 is located at the
abutment position, it is difficult for a user to insert a sheet to
a position between the manual feed tray 111 and the pickup roller
113. Therefore, when an initial position of the pickup roller 113
is set to the abutment position of the pickup roller 113 regardless
of a state of the apparatus or presence of the sheet placed on the
manual feed tray 111, usability may be deteriorated.
[0078] Further, under a state in which the fixed size mode is not
enabled, it is assumed that a sheet to be used with the manual feed
tray 111 is different every time. Therefore, when the manual feed
tray 111 is to be used, it is necessary that a user set a sheet on
the manual feed tray 111, adjust the manual feed side regulation
guides 212 and 213 to a sheet width, and select through the
operation unit a size of the sheet to be used. When a system is
employed in which the pickup roller 113 is moved to the abutment
position at the timing of detecting that a sheet is present, the
pickup roller 113 is located at the abutment position while a user
is setting the sheet on the manual feed tray 111. Thus, usability
is deteriorated when a user adjusts the manual feed side regulation
guides 212 and 213 to correctly set a sheet.
[0079] In contrast, under a state in which the fixed size mode is
enabled, a size of a sheet to be used is settled in advance. Thus,
it is highly probable that the sheet to be set on the manual feed
tray 111 is the same every time. In other words, it can be
considered that the positions of the manual feed side regulation
guides 212 and 213 are often already adjusted to a width of the
sheet to be set, and hence a user needs not make adjustment over
again.
[0080] Thus, even when the pickup roller 113 is moved to the
abutment position after it is detected that a sheet of a designated
size is present on the manual feed tray 111, it is less likely to
cause a hindrance, such as requiring a user to set a sheet again.
Therefore, usability under a state in which the fixed size mode is
enabled can be maintained. From the description above, even when
the pickup roller 113 is moved to the abutment position at the
point of time when a user sets a sheet having a designated size on
the manual feed tray 111, the FCOT can be shortened without
deteriorating usability.
[0081] As described above, when the fixed size mode is enabled, a
sheet to be set on the manual feed tray 111 has a designated size,
and hence it is highly probable that the positions of the manual
feed side regulation guides 212 and 213 are already adjusted to the
width of the sheet to be set. Therefore, the pickup roller 113 may
be moved to the abutment position based on the detection that a
sheet is placed rather than on the condition that the size of the
sheet placed on the manual feed tray 111 matches with the
designated size.
<Flow of Detecting Sheet Placed on Manual Feed Tray 111>
[0082] FIG. 9 is a flowchart for illustrating a control to be
executed by the CPU 301 after detection of a sheet set on the
manual feed tray 111 when the fixed size mode is enabled.
[0083] When the fixed size mode is enabled, the sheet size has
already been selected through the UI 330, and hence information
related to the sheet size is stored in the RAM 303. As described
with reference to FIGS. 7, for example, when a user sets the A4
size in the fixed size mode, information indicating designation of
the A4 size as the sheet size is stored in the RAM 303. This
information indicating designation of the A4 size is maintained in
the RAM 303 until the fixed size mode is disabled.
[0084] As illustrated in FIG. 9, the CPU 301 detects whether or not
a sheet is set on the manual feed tray 111 (Step S1122). After
that, the CPU 301 determines through the sheet sensor 115 whether
or not the sheet is present on the manual feed tray 111 (Step
S1123). When it is determined that no sheet is present (Step S1123:
N), the CPU 301 determines that a sheet is removed, and the flow is
terminated. When it is determined that a sheet is present (Step
S1123: Y), the CPU 301 stores in the RAM 303 the above-mentioned
size detection result on the manual feed tray 111 as the detected
size (Step S1124).
[0085] After the detected size is settled, the CPU 301 determines
whether or not the sheet size set by a user in the fixed size mode
matches with the detected size (Step S1125). When the sizes do not
match (Step S1125: N), processing of the CPU 301 returns to the
Step S1123.
[0086] As one example, there is a case where a sheet having a size
different from the set fixed size is erroneously set on the manual
feed tray 111 by a user. In this case, a user needs to remove the
sheet from the manual feed tray 111 to replace it with a sheet
having a correct size on the manual feed tray 111. At this time,
when the pickup roller 113 is located at the abutment position,
usability during the replacement operation may be deteriorated as
described above. Thus, at this point of time, the control of
causing the pickup roller 113 to be moved to the abutment position
is not performed.
[0087] Meanwhile, when the detected size matches with the fixed
size (Step S1125: Y), it can be considered that the operation of
the manual feed side regulation guides 212 and 213 by a user is
completed. In other words, the operation by a user is not bothered
by the movement of the pickup roller 113 to the abutment position.
Thus, the CPU 301 executes a pickup roller lowering sub-flow
illustrated in FIG. 10 described later to cause the pickup roller
113 to be moved to the position held in abutment against the manual
feed tray 111.
<Pickup Roller Lowering Sub-flow>
[0088] FIG. 10 is a flowchart for illustrating the pickup roller
lowering sub-flow. When it is determined in the Step S1125 of FIG.
9 that the detected size and the sheet size are equal (Step S1125:
Y), the CPU 301 executes a control of lowering the pickup roller
113 prior to receiving the printing start instruction (Step S2112).
Specifically, as illustrated in FIG. 8C, the raising and lowering
motor 163 is driven for the time period Ta (Step S2112).
[0089] Next, in order to prevent the lowered pickup roller 113 from
being maintained at the abutment position for a long time, the
timer 291 is set so that elapse of a predetermined time period can
be determined (Step S2114). In this example, the predetermined time
period is set as 30 seconds.
[0090] The CPU 301 determines through the sheet sensor 115 whether
or not a sheet is present on the manual feed tray 111 (Step S2116).
When a sheet is not detected by the sheet sensor 115 (Step S2116:
N), the CPU 301 updates the sheet size information stored in the
RAM 303 to "size unsettled", and causes the pickup roller 113 to be
raised and moved to the separation position (Step S2126).
[0091] With this, the pickup roller 113 is separated from the
manual feed tray 111, and hence a user can set a sheet on the
manual feed tray 111. Specifically, the CPU 301 drives the raising
and lowering motor 163 until the ON edge of the pickup roller HP
sensor 167 is detected, and then terminates the processing.
[0092] Meanwhile, when the sheet sensor 115 detects a sheet (Step
S2116: Y), it is determined through the timer 291 whether or not
the predetermined time period has elapsed (Step S2118). When the
predetermined time period has elapsed (Step S2118: Y), the CPU 301
executes the processing of the above-mentioned Step S2126 to cause
the pickup roller 113 to be moved to the separation position, and
then terminates the processing.
[0093] When the pickup roller 113 is left for a long time under a
state of being held in abutment against a sheet, a roller trace may
remain on the uppermost sheet stacked on the manual feed tray 111.
Accordingly, in this embodiment, elapse of the predetermined time
period is detected to thereby detect that sheet feeding is not
performed even after elapse of the predetermined time period. In
this case, printing is unlikely to be started, and hence the CPU
301 causes the pickup roller 113 to be moved to the separation
position.
[0094] When the predetermined time period has not elapsed (Step
S2118: N), the CPU 301 determines whether or not printing
processing is started in accordance with the printing start
instruction (Step S2122). When the printing processing is not
started (Step S2122: N), the CPU 301 executes the processing of
Step S2116. When the printing processing is started (Step S2122:
Y), the CPU 301 terminates the processing.
<Control Flow Executed Upon Powering on or Recovering From
Power-Saving Mode>
[0095] FIG. 11 is a flowchart for illustrating a control executed
by the CPU 301. This control is executed when the image forming
apparatus 10 according to the first embodiment is powered on or
recovered from a power-saving mode, while the fixed size mode is
enabled.
[0096] The CPU 301 determines through the sheet sensor 115 whether
or not a sheet is placed on the manual feed tray 111 (Step S3122).
When a sheet is not detected (Step S3122: N), the CPU 301
terminates the processing. When a sheet is detected (Step S3122:
Y), the CPU 301 stores in the RAM 303 the size detection result on
the manual feed tray 111 as the detected size (Step S3123).
[0097] After the detected size is settled, the CPU 301 determines
whether or not the sheet size set by a user in the fixed size mode
matches with the detected size (Step S3124). When the sizes do not
match (Step S3124: N), the CPU 301 executes processing of detecting
whether or not a sheet is set on the manual feed tray 111 described
with reference to FIG. 9 (Step S1122). When the detection result
matches (Step S3124: Y), the CPU 301 executes the pickup roller
lowering control processing described with reference to FIG. 10
(Step S2112). Through the control described above, even when
printing processing or the like is required to be started
immediately after the image forming apparatus 10 is powered on or
recovered from the power-saving mode, the FCOT can be shortened
while maintaining usability.
<Control Flow Executed at the Time of Starting Print Job>
[0098] FIG. 12 is a flowchart for illustrating a control which is
executed at the time of starting printing processing in the image
forming apparatus 10.
[0099] After the printing processing start instruction is received,
the CPU 301 determines whether or not the pickup roller 113 is
located at the abutment position (Step S5114). When the pickup
roller 113 is located at the abutment position (Step S5114: Y),
sheet feeding is started (Step S5116). When the pickup roller 113
is not located at the abutment position (Step S5114: N), the CPU
301 causes the pickup roller 113 to be lowered and moved to the
abutment position (Step S5115), and executes the processing of Step
S5114 again. After that, when the pickup roller 113 is lowered to
the abutment position, the determined result Y is attained in the
processing of Step S5114, and then sheet feeding is started (Step
S5116).
[0100] After sheet feeding is started, the CPU 301 determines
whether or not printing processing has been completed (Step S5117).
When the printing processing has not been completed (Step S5117:
N), the processing of Step S5117 is executed again. When the
printing processing has been completed (Step S5117: Y), the CPU 301
executes a control of causing the pickup roller 113 to be moved to
the separation position (Step S5118) and terminates the
processing.
[0101] With regard to Step S5114 of FIG. 12, there is a case where
the fixed size mode is enabled as illustrated in Step S3122 to Step
3124 of FIG. 11. In this case, the pickup roller 113 is moved to
the abutment position at a timing of the detection in FIG. 11 that
a sheet is present on the manual feed tray 111 (Step S3122: Y).
[0102] Generally, a user gives a printing processing start
instruction after setting a sheet on the manual feed tray 111.
Therefore, in FIG. 12, the detection result Y is attained in the
processing of Step S5114 executed after starting the printing
processing. However, as described with reference to FIG. 10 for
example, there is also a case where the printing processing is not
performed even after elapse of a predetermined time period since a
sheet is set by a user on the manual feed tray 111 (Step S2118:
Y).
[0103] In this case, as illustrated in FIG. 10, the CPU 301 causes
the pickup roller 113 to be raised and moved to the separation
position (Step S2126). In such a case, the determined result N is
attained in Step S5114 of FIG. 12, and the processing of Step S5115
is executed.
[0104] Meanwhile, in this embodiment, the control of causing the
pickup roller 113 to be moved to the abutment position prior to the
printing processing is not executed under a state in which the
fixed size mode is disabled. Thus, in this case, the determined
result N is attained in Step S5114 of FIG. 12 (Step S5114: N), and
the CPU 301 executes the control of causing the pickup roller 113
to be moved to the abutment position in Step S5115.
[0105] As described above, according to the present invention, when
the fixed size mode is enabled, and it is detected that a sheet is
placed on the manual feed tray 111, the pickup roller 113 has
already been moved to the abutment position. Accordingly, with the
pickup roller held in abutment against the sheet, sheet feeding can
be started promptly after starting printing while maintaining
usability at the time of enabling the fixed size mode. Thus, the
time having been required for the pickup roller to be brought into
abutment against the sheet may be shortened, and hence the first
copy time can be shortened.
[0106] The present invention is not limited to the above-mentioned
embodiment, and can be practiced in various modes. For example, the
mechanical configuration and the raising and lowering conditions of
the raising and lowering motor 163, the pickup roller 113, and the
pickup roller HP sensor 167 illustrated in the first embodiment are
mere examples.
[0107] Further, in the first embodiment, the configuration of
fixing the manual feed tray 111 and raising and lowering the pickup
roller 113 is employed so that the pickup roller 113 and the sheet
are brought into abutment against each other or separated from each
other. However, the configuration of fixing the pickup roller 113
and raising and lowering the manual feed tray 111, or the
configuration of allowing both the pickup roller 113 and the manual
feed tray 111 to be raised and lowered concurrently may also be
employed. In other words, it is only necessary that at least one of
the pickup roller 113 and the manual feed tray 111 be moved in a
direction of allowing the pickup roller 113 and the manual feed
tray 111 to approach to each other or separate from each other.
[0108] As described above, according to the present invention, when
a size of a sheet to be fed is designated by a user in advance, and
it is determined that a sheet is placed on the manual feed tray, at
least one of the sheet-feeding unit and the manual feed tray is
moved. This movement is performed so that the sheet-feeding unit
and the manual feed tray are located at positions of enabling the
sheet-feeding unit to feed a placed sheet. Thus, a delay time until
sheet feeding is enabled can be shortened.
[0109] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0110] This application claims the benefit of Japanese Patent
Application No. 2015-174950, filed Sep. 4, 2015 which is hereby
incorporated by reference herein in its entirety.
* * * * *